In clamping chucks of said type, different tools, which can be inserted into a receiving opening in the body of the clamping chuck, can be fixed in non-positively locking fashion for the purpose of then performing a material machining process by means thereof. Said clamping chucks are suitable both for static machining and also for rotary machining, in which the tool is conventionally set in rotational motion.
In the present disclosure, the expressions “axial” and “radial” are used in relation to the direction of extent of the receiving opening in the working direction, which in the case of rotary tools normally coincides with the axis of rotation of said rotary motion.
The fixing of the respective tool is in this case generally realized by virtue of the tool being firmly clamped within the receiving opening by means of a local deformation of the wall of the receiving opening. This may for example be achieved by virtue of a chamber being provided within the body of the clamping chuck, into which chamber a hydraulic liquid can be introduced at such a high pressure that a partition wall between the chamber and receiving opening is deformed reversibly in the radial direction such that the cross section of the receiving opening is reduced, and the tool inserted into said receiving opening is firmly clamped.
For this purpose, however, high pressures are required, which pressures furthermore vary depending on the cross section of the receiving opening. If pressures from 120 000 000 Pa (1200 bar) to 150 000 000 Pa (1500 bar) are typically required for receiving openings with an 8 mm cross section, this rises to as high as 400 000 000 Pa (4000 bar) to 500 000 000 Pa (5000 bar) for a 3 mm cross section. This can have the effect that the range of elastic deformations is departed from and plastic deformations begin to occur. The cross-sectional reduction that can be effected in this way is thus limited.
It is known from the prior art to circumvent this problem by virtue of a reducing sleeve being arranged in the receiving opening of the clamping chuck. This eliminates the need to work with small cross sections and extremely high pressures. In general, the reducing sleeve, like the tool itself, can be exchanged and thus adapted for example to the tool diameter. A problem here is however the fact that radial run-outs can arise, specifically with greater intensity the longer the clamping chuck and tool are. Eccentricities of clamping chuck and reducing sleeve can add up. An example of such clamping chucks is known for example from DE 94 112 60.
Accordingly, it would be desirable to provide an improved clamping chuck with a reducing sleeve.